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<title>Boost Graph Library: random</title>

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<br>

The header <tt>&lt;boost/graph/random&gt;</tt> provides routines to create
random graph, select random vertices and edges, and randomize properties.

<h1>Synopsis</h1>

<pre>

  template &lt;class Graph, class RandomNumGen&gt;
  typename graph_traits&lt;Graph&gt;::vertex_descriptor
  random_vertex(Graph&amp; g, RandomNumGen&amp; gen);

  template &lt;class Graph, class RandomNumGen&gt;
  typename graph_traits&lt;Graph&gt;::edge_descriptor
  random_edge(Graph&amp; g, RandomNumGen&amp; gen);

  template &lt;typename MutableGraph, class RandNumGen&gt;
  void generate_random_graph
    (MutableGraph&amp; g,
     typename graph_traits&lt;MutableGraph&gt;::vertices_size_type V,
     typename graph_traits&lt;MutableGraph&gt;::vertices_size_type E,
     RandNumGen&amp; gen,
     bool self_edges = false);

  template&lt;class Property, class G, class RandomGenerator&gt;
    void randomize_property(G&amp; g, RandomGenerator rg);

</pre>

<h1>Description</h1>

<h2 id="random_vertex">random_vertex</h2>

<pre>
  template &lt;class Graph, class RandomNumGen&gt;
  typename graph_traits&lt;Graph&gt;::vertex_descriptor
  random_vertex(Graph&amp; g, RandomNumGen&amp; gen);
</pre>

<p><b>Effects:</b> Selects a random vertex in a graph and returns it.
<p><b>Preconditions:</b> <tt>num_vertices(g) != 0</tt>
<p><b>Complexity:</b> <tt>O(num_vertices(g))</tt>

<h2 id="random_edge">random_edge</h2>

<pre>
  template &lt;class Graph, class RandomNumGen&gt;
  typename graph_traits&lt;Graph&gt;::edge_descriptor
  random_edge(Graph&amp; g, RandomNumGen&amp; gen);
</pre>

<p><b>Effects:</b> Selects a random edge in a graph and returns it.
<p><b>Preconditions:</b> <tt>num_edges(g) != 0</tt>
<p><b>Complexity:</b> <tt>O(num_edges(g))</tt>

<h2 id="generate_random_graph">generate_random_graph</h2>

<pre>
  template &lt;typename MutableGraph, class RandNumGen&gt;
  void generate_random_graph
    (MutableGraph&amp; g,
     typename graph_traits&lt;MutableGraph&gt;::vertices_size_type V,
     typename graph_traits&lt;MutableGraph&gt;::vertices_size_type E,
     RandNumGen&amp; gen,
     bool allow_parallel = true,
     bool self_edges = false);
</pre>

<p><b>Effects:</b> Adds <tt>V</tt> vertices and <tt>E</tt> edges, to
<tt>g</tt>. Source and target vertices of each edge are randomly choosen. If
<tt>self_edges</tt> is false, then no edge will have the same source and
targets.
<p><b>Precondition:</b> <tt>num_vertices(g) == 0</tt>
<p><b>Compleixity:</b> <tt>O(V*E)</tt>

<h2 id="randomize_property">randomize_property</h2>

<pre>
  template&lt;class Property, class G, class RandomGenerator&gt;
    void randomize_property(G&amp; g, RandomGenerator&amp; rg);
</pre>

<p><b>Effects:</b> Sets the random value of property on either all vertices, or
all edges, depending on property kind.
<p><b>Complexity:</b> <tt>O(V)</tt> or <tt>O(E)</tt>, depending on property
kind.

<hr>

<p class="revision">Last modified: Feb 05, 2003</p>

<p>&copy; Copyright Vladimir Prus 2003. Permission to copy, use, modify,
sell and distribute this document is granted provided this copyright
notice appears in all copies. This document is provided ``as is'' without
express or implied warranty, and with no claim as to its suitability for
any purpose.</p>

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